Cheating? In NASCAR? Really? Next you're going to tell us professional wrestling isn't real, or that Al Gore really didn't invent the Inter-web.

Defining cheating in NASCAR is as much an art as getting away with an oversized carburetor. (To younger readers: A carburetor is a device that was used in the rest of the world before fuel injection was invented, but is still used in NASCAR. And no, we aren't sure why.)

We can all agree that cheating happens when you break a rule. But there are a lot of gray areas in motorsports, though NASCAR does have that clause in the rule book—which we've seen, but weren't supposed to, since it's secret—regarding "actions detrimental" to the sport. That can cover anything.

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But for decades, mechanics and crew chiefs have done their best to work around NASCAR's rules. Smokey Yunick, the legendary Daytona Beach mechanic, used to insist that it wasn't cheating if the rules didn't say you couldn't do it (see number 2 below). Every year, the NASCAR rule book gets a little thicker, a little less gray. "It can be frustrating," says Chad Knaus, crew chief for four-time champion Jimmie Johnson. Knaus has had his share of run-ins with NASCAR inspectors (see number 3). "But it would be more frustrating to give up trying to make our car better."

In no particular order, here are 10 choice tales of cheating in NASCAR.

1. The First Race, the First Cheater

On June 19, 1949, the very first NASCAR "strictly stock" race was held in Charlotte, North Carolina. Founder Bill France insisted that since the "SC" in NASCAR stood for "Stock Car," that his race not be populated by backyard-built, chopped-and-channeled hot rods, but by cars that actually looked like, well, cars. So a large percentage of the field of 33 vehicles came straight from a local dealership.

The race took place on a three-quarter-mile dirt oval track, for 150 miles. The winner was Glenn Dunaway, who drove Herbert Westmoreland's 1947 Ford all 200 laps, finishing three laps ahead of second place, Jim Roper, who had read about the race in a comic strip and showed up in a Lincoln. When the dust cleared—literally—it was Roper who was declared the winner, because there was evidence that Westmoreland's Ford, a genuine moonshine-runner, had modified rear springs. Dunaway ended up last, and Roper won the $2,000 purse. Westmoreland promptly filed a $10,000 lawsuit, which was thrown out of court. This was a good thing for Bill France: He went into his second race with the courts having already affirmed his right to throw out a competitor.

But with as few as 15 cars showing up for some of the rest of the eight-race 1949 season, France wasn't anxious to kick out any other competitors. It was not until July 31, 1951, that another winner, Jim Delaney at Rochester, New York, was disqualified, this time for a non-stock camshaft.

2. Reading Between the Lines

Smokey Yunick, owner of Daytona's Best Damn Garage in Town, was a perpetual thorn in the side of NASCAR in general, and Bill France in particular. The self-taught engineer was a genius at aerodynamics, and his tricks to make a car's body slip through the air were far ahead of his time. But Yunick was perhaps best known for interpreting what the rule book said—or, perhaps, didn't say. For example: In 1968, he said NASCAR specified how big a fuel tank could be, but he noticed no one said how big the fuel line could be. Instead of a half-inch fuel line, Yunick created a two-inch fuel line that was 11 feet long, and held five gallons of gas. Cheating? Not really, since nowhere did it say you couldn't do that.

3. Excellence Has a Price

The quieter, far less flamboyant modern-day Yunick-equivalent has to be Chad Knaus, the bookish crew chief behind Jimmie Johnson's four Sprint Cup championships. His run-ins with NASCAR inspectors were almost nonstop, at least until the current "Car of Tomorrow" became more tightly defined. In 2005, NASCAR found Knaus's carefully engineered shock absorbers so ingenious that they cited his brilliance before penalizing him, and declaring the shock illegal. In fact, Knaus has been suspended four times in six seasons. After winning the Daytona 500 in 2006, The New York Times wrote that there was a "stigma attached" to Jimmie Johnson's win, because Knaus had been suspended for four races and fined $25,000 for a device mounted to the rear window that changed its angle, making it more aerodynamic.

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4. Triumph and Tragedy

Daytona 500, 2001: The 2001 Daytona 500 was perhaps the greatest triumph of NASCAR inspectors over innovation. Eighteen teams were fined for cheating, with infractions that included illegal fuel additives, an illegal air deflector, an illegal fuel tank, illegal control arms, and illegal suspension modifications. But NASCAR maybe should have been paying more attention to driver safety than air deflectors: That was the year Dale Earnhardt was killed at Daytona, a death that could have been prevented had NASCAR mandated one of the already-popular head and neck restraints.

5. First Place, for Once

Country singer Marty Robbins ("El Paso") was an avid NASCAR fan and a part-time driver who actually ran many of the big super speedway races including Talladega in 1973, when he stunned the competition by turning laps that were 15 mph faster than his qualifying time. Apparently, in his motel room, Robbins had knocked the NASCAR-mandated restrictors out of his carburetor. After the race, NASCAR tried to give him the Rookie of the Race award, but Robbins wouldn't accept it, admitting he was illegal because he "just wanted to see what it was like to run up front for once."

6. Playing the Wrong Sport

Another Smokey Yunick story: NASCAR mandated how much a gas tank could hold, which Yunick once circumvented by placing a basketball in the tank and inflating it with air. NASCAR checked the tank's capacity and cleared it. Then, when no one was looking, Yunick deflated the basketball.

7. Rocket Fuel… Really?

There was nothing funny about the cheating incident at the Daytona 500 in 2007, when Toyota's heralded debut was tainted by team owner Michael Waltrip, who apparently put an illegal fuel additive into the Toyota's tank before qualifying. Incorrectly described by much of the media as "rocket fuel"—the impression being that all you needed to do to turn a pushrod V-8 into a rocket was add rocket fuel—it was some sort of oxygenator. The move was so stupid that the perpetrator had to be a rank amateur (or a smart saboteur, many thought), but the result was enormous fines and disqualification for Waltrip, who barely made the 500 by coming up through the qualifying races. There is no gray area to a fuel additive—NASCAR was infuriated and went on a bit of a rampage, suspending crew chiefs of four other teams for various lesser infractions. It was the most serious crackdown since 1976 at Daytona.

8. Everybody's Doing It

And what happened in 1976? The three fastest qualifiers for the 500—A.J. Foyt, Dave Marcis and Darrell Waltrip—had their times rejected. Marcis for illegal, but comparatively minor, alterations to the radiator, and Foyt and Waltrip for apparently rigging their cars to use nitrous oxide. Waltrip, at least, was unrepentant. "If you don't cheat," he said, "you look like an idiot."

9. Saved by the Bell

Another day that lives on in NASCAR cheating infamy was October 9, 1983, at Charlotte Motor Speedway, when Richard Petty sailed to a win. NASCAR inspectors found two reasons: One, his crew had put left-side tires on the right side, and vice-versa, which would have made for a nice, if brief, advantage. Even a bigger advantage: Petty's engine measured 381.983 cubic inches, compared to the legal 358. Stunningly, though Petty was fined, he was allowed to keep the victory, because years earlier, Bill France had decided that whoever won when the fans were leaving the track could keep the win, because he didn't want them reading about big changes made afterwards in the next day's newspaper.

10. Wood Weighs Less Than Steel

In 1952, Tim Flock, who used to race with his pet monkey, Jocko Flocko, in the cockpit, was disqualified from a NASCAR modified race because his roll bars were made from painted wood.

11. Heavy Metal

NASCAR used to weigh the cars to make sure they were at the minimum before the race, but not after, and teams would do all sorts of things to get the cars through inspection, including placing solid lead radios and helmets in the car as they rolled across the scale. Darrell Waltrip's team would fill frame rails with BBs or buckshot, then when on the track, he'd pull a little wire that would open a trap door in the frame rail, and the BBs would spill out on the back straight. But once, a crewman washed the car and got the BBs wet. They all stuck together, and didn't escape until Waltrip was speeding down pit lane. As the BBs pelted crew members from other teams, as well as NASCAR officials, it did not take long for inspectors to close that loophole.